<html> 
<body> 
   
    <table border="1"> 
        <tr> 
            <th><input type="checkbox" onclick="swapCheck()" /></th> 
            <th>Month</th> 
            <th>Savings</th> 
        </tr> 
        <tr> 
            <td><input type="checkbox" /></td> 
            <td>January</td> 
            <td>$100</td> 
        </tr> 
        <tr> 
            <td><input type="checkbox" /></td> 
            <td>February</td> 
            <td>$150</td> 
        </tr> 
    </table> 
   
    <script type="text/javascript" 
        src="http://apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script> 
   
    <script type="text/javascript"> 
        //checkbox 全选/取消全选 
        var isCheckAll = false; 
        function swapCheck() { 
            if (isCheckAll) { 
                $("input[type='checkbox']").each(function() { 
                    this.checked = false; 
                }); 
                isCheckAll = false; 
            } else { 
                $("input[type='checkbox']").each(function() { 
                    this.checked = true; 
                }); 
                isCheckAll = true; 
            } 
        } 
    </script> 
   
</body> 
</html>